Does replying to your own message count as an additional post?

There used to be a feature whereby when one would reply to one's own post the response would be added to the previous post as opposed to posted as an additional post. This seems to have been lifted, ie a reply to one's own post is in fact an additional post. What exactly is the rule? And is it true that this has been lifted?

I sometimes add another post by replying to my own but it will automatically update the previous post, if nobody squeezed another post inbetween. This reply will also update the timestamp of the last post so that others see there has been some action on this thread.

Edit:
To your question in the subject: Yes, the post counter is increased, but as explained above, it is include in the last of your post as long no one other posted another reply.

Thank you for your response. My question was indeed only about where the own response appears (provided that no one answered in between). It used to be outside the post (ie an additional one), then about a year ago it was within the post and currently it is again outside the post. Whether the post count goes up is immaterial to me.